Experts say the drug that has kept Barbara Bradfield healthy for so long, Herceptin, has changed the nature of breast cancer and helped doctors better understand what causes the disease. In the 10 years since it was approved, doctors say Herceptin also has encouraged the development of a growing arsenal of new therapies that target cancer cells but spare patients from many of the grueling side effects of traditional chemotherapy.

Bad advice, or just too much of it, can compound the trauma and damage done by the disease itself, cancer patients often find. Friends and relatives are important for support, but when these untrained people act as cancer coaches, they can sway people to make poor decisions about their care.